Properties of the Two-Dimensional Electron Gas Confined in GaN/AlGaN Interface Studied by Electron Spin Resonance

Abstract

In this communication we report results of electron spin resonance investigations on the high‐mobility two‐dimensional electron gas confined at the GaN/AlGaN interface. On one spectrum we observe simultaneously Shubnikov ‐ de Haas oscillations, magnetoplasma resonance, and a narrow resonance line with g‐factor close to 2. From the period of the Shubnikov ‐ de Haas oscillations we calculate the sheet carrier density, 1.9*1012 cm−2. The lineshape of the magnetoplasma resonance is well described assuming the Drude model of relaxation with resonance frequency given by the standard formula for the lower branch of the coupled plasma‐cyclotron mode. The plasma frequency obtained from the fit of the lineshape yields the same sheet carrier density as that determined from Shubnikov ‐ de Haas oscillations. The mobility of the two‐dimensional electrons determined from the fit equals to 120 000 cm2/Vs. The correlation of the resonance line at g = 2 with the two‐dimensional electrons is discussed.